If you just want to see pretty graphs and don't need complex investigative features, Neo4j is the standard. The Community Edition is free.
Maltego is the closest functional cousin to i2, but it operates differently. i2 analyst notebook free alternative
| Feature | i2 Analyst’s Notebook | Maltego CE | Linkurious OGMIEN | Gephi | |-------------------------------|----------------------|------------|-------------------|-----------| | Free | ❌ ($$$) | ✅ (limited) | ✅ (open-source) | ✅ | | Link chart creation | ✅ | ✅ | ✅ | ✅ | | Timeline view | ✅ | ❌ | ❌ (plugin avail.) | ❌ | | Geospatial view | ✅ | ❌ | ✅ (plugin) | ❌ | | OSINT transforms | Limited | ✅ | ❌ (manual import) | ❌ | | Social network metrics | ✅ | Basic | Basic | Advanced | | CSV/Excel import | ✅ | Limited | ✅ (via Neo4j) | ✅ | | Learning curve | Moderate | Moderate | Steep | Steep | If you just want to see pretty graphs
Proprietary free viewer Best for: Geospatial intelligence (GEOINT) and imagery analysts. | Feature | i2 Analyst’s Notebook | Maltego